Processing Aids and Polymer Formulations Containing the Same and Method for Producing the Same

ABSTRACT

A multi-stage emulsion processing aid polymer comprising one or more functionalized ethylenically unsaturated monomer into the emulsion polymerization reactor, wherein the functionality is selected from the group consisting of β-keto esters, β-keto amides, β-diketones, cyanoacetic esters, malonates, nitroalkanes, β-nitro esters, sulfonazides, thiols, thiol-s-triazines, and amine, where the functionality is incorporated into polymers by polymerizing, ethylenically unsaturated monomers containing these functionalities or by post functionalization of a polymer with additional reactions after polymerization in one of the first or second stages. Foamable halogenated polymers comprising the multi-stage emulsion processing aid polymer is also provided. Also provided are methods for making the multi-stage emulsion processing aid polymer and foamable halogenated polymers.

FIELD OF INVENTION

This invention relates to a multi-stage emulsion processing aid polymer,a foamable halogenated polymer formulation comprising the processing aidpolymer, method of producing processing aids and method of producing thefoamable polymer formulation.

BACKGROUND OF THE INVENTION

Halogenated polymers such as polyvinyl chloride (“PVC”) are employed asbuilding materials to replace wood in a variety of applications such ashouse fascia, trim, and decorative molding mill work. “Halogenatedpolymers” as used herein means (1) homopolymers or copolymers containinggreater than 80% of vinyl chloride, vinyl fluoride, vinylidene chloride,vinylidene fluoride, or combinations and (2) chlorinated polyvinylchloride, chlorinated polyethylene, or combinations thereof. The mostcommon of these polymers industrially is polyvinyl chloride (PVC) so thegeneral description herein will emphasize PVC and foamed PVC asexamples. PVC foam is also used for signage, deck boards, and in thecores of some types of PVC pipe.

Foamed PVC for these various applications is typically made in acontinuous extrusion process. The most common extrusion practicesinvolve free foaming out of the die followed by some type of calibrationand the Celuka or integrated skin process. A description of these PVCfoaming processes and typical formulation ingredients can be found in D.Klempner and V. Sendijarevic, “PVC Foams”, Chapter 9, Handbook ofPolymeric Foams and Foam Technology, 2nd Ed., Hanser Publishers, Munich(2004).

Key components of foamed PVC formulations are PVC, thermal stabilizer,lubricants, one or more blowing agents, and (co)polymers additives suchas impact modifiers and processing aid polymers. The processing aidpolymers are materials that are compatible with PVC and tend to becopolymers that are high in methyl methacrylate or other compositionsthat are compatible with PVC, for example, styrene acrylonitrilecopolymers. U.S. Pat. Nos. 2,646,417, 3,975,315, 5,206,296, and6,765,033 and European Patent No. EP 1153936 describe the types ofpolymer compositions used as processing aids for PVC. “Compatible” asused herein means that the processing aid polymer mixes or dispersesuniformly into the PVC during thermal processing.

High molecular weight processing aids provide polymer expansion or dieswell during polymer processing when the heated polymer exits theextruder die. This expansion is important in processes such as theCeluka process in which polymer expansion is required to fill the cavityor in free foam where a certain sheet thickness is required. Theseprocessing aid polymers also increase melt extensibility and strengthdue to their high molecular weight and compatibility with PVC . This inturn helps control the foam cell expansion and provides a small uniformcell size. Additionally, high melt strength helps prevent foam collapsewhile the extruded foam sheet is cooling and helps lock in the foamstructure. High melt strength, in addition, allows the pulling of hotextruded material through sizing or calibrating equipment. Any scrap ortrim material can be ground up and reused in the extrusion process inthat the foamed material is a thermoplastic and not a cross linkedthermoset material. Being able to recycle the material as regrind isimportant for economics and waste handling.

It is not unusual for these processing aids to have weight averagemolecular weights in the 0.5 to 15 million range with the higher MWmaterials showing greater efficiency (B. Haworth et al., Plastics,Rubber and Composites Processing and Applications, vol. 22, p. 159,1994). Use levels can fall in the range of 0.5 to 20 parts per hundredon PVC in the formulation depending on the processing aid MW, thedesired density, and sheet thickness. Lower density and higher sheetthickness require higher processing aid use levels.

An alternative to the use of high MW processing aids to allow foaming isto use a cross linking agent for the matrix polymer. The cross linkingagent must cure at a temperature and rate similar to the decompositionof the chemical blowing agents to set the foam. This approach is used inindustry to make polyurethane, epoxy foams, and the like D. Klempner andV. Sendijarevic, Handbook of Polymeric Foams and Foam Technology, 2ndEd., Hanser Publishers, Munich (2004).

This curing approach has also been used for halogenated polymers likePVC. In a typical approach, PVC, blowing agent, and cross linking agentare combined together and placed in a mold under pressure. The mold isheated to the temperature that causes the blowing agent to generate gasand the pressure is released causing foaming and curing to occur in thesame time frame. In this way, the foam structure is locked in and athermoset material is generated that has high heat resistance andresistance to compression set, but scrap from the foam cannot easily bereprocessed. Also, this type of approach does not lend itself toextrusion type foaming processes as curing tends to occur inside theextruder.

Examples for this type of approach include U.S. Pat. No. 3,261,785,where a non-polymeric poly functional sulfonazide is used as a crosslinker for PVC. In U.S. Patent No. 4,956,222, an isocyanate curing agentis used with plasticized PVC where the PVC contains active hydrogenfunctionality, or an acrylic polymer with active hydrogen functionalityis blended with the PVC and cured with an isocyanate. In EuropeanPolymer Journal, vol. 36, p. 2235 (2000), cross linking of PVC foamthrough the use of peroxides and trimethacrylate monomers is described.These approaches have the limitations that scrap cannot be reprocessed.Also, this type of approach does not lend itself to extrusion typefoaming processes as controlling the curing rate so that the materialdoes not cure in the extruder and cause melt viscosity issues isdifficult.

SUMMARY OF THE INVENTION

The instant invention is a processing aid, foamable halogenated polymerformulations containing the processing aid, and method of producing theprocessing aids and polymer formulations. We have found that by stagingthe addition of the functionalized ethylenically unsaturated monomer inone stage of a multi-stage polymerization, we can further increase theutility of U.S. application Ser. No. 12/283,934, filed on Sep. 17, 2008,which claimed priority to U.S. Provisional Application No. 60/997,880,filed on Oct. 5, 2007, by increasing the molecular weight of the polymerat a constant functionalized ethylenically unsaturated monomer level.

The invention provides a multi-stage emulsion processing aid polymercomprising from 25 to 75 percent by weight first stage polymer whichcomprises units derived from non-functional ethylenically unsaturatedmonomer; and from 25 to 75 percent by weight second stage polymer whichcomprises units derived from one or more functionalized ethylenicallyunsaturated monomer into the emulsion polymerization reactor, whereinthe functionality is selected from the group consisting of β-ketoesters, β-keto amides, β-diketones, cyanoacetic esters, malonates,nitroalkanes, β-nitro esters, sulfonazides, thiols, thiol-s-triazines,and amine, where the functionality is incorporated into polymers bypolymerizing, ethylenically unsaturated monomers containing thesefunctionalities or by post functionalization of a polymer withadditional reactions after polymerization; and wherein the processingaid polymer has a Mw equal to or greater than 700,000. In suchembodiment, the first stage contains no units derived fromfunctionalized monomers.

In alternative embodiments, the invention provides a processing aidpolymer wherein the functional group is in the first stage of amulti-stage polymer, foamable halogenated polymer formulationscontaining the inventive processing aids, and methods of producing theprocessing aids and the foamable halogenated polymer formulations.

DETAILED DESCRIPTION OF THE INVENTION

The instant invention is a multi-stage emulsion processing aid polymer,foamable halogenated formulation containing the processing aid polymer,method of producing processing aids and method of producing the foamablehalogenated polymer formulations containing the same.

A first embodiment of the multi-stage emulsion processing aid polymercomprises: from 25 to 75 percent by weight first stage polymer whichcomprises units derived from non-functional ethylenically unsaturatedmonomer; and from 25 to 75 percent by weight second stage polymer whichcomprises 0 to 99.6 mole % units derived from one or more non-functionalethylenically unsaturated monomer(s) and 0.4 to 100 mole % units derivedfrom one or more functionalized ethylenically unsaturated monomer(s)into the emulsion polymerization reactor, wherein the functionality isselected from the group consisting of β-keto esters, β-keto amides,β-diketones, cyanoacetic esters, malonates, nitroalkanes, β-nitroesters, sulfonazides, thiols, thiol-s-triazines, and amine, where thefunctionality is incorporated into polymers by polymerizing,ethylenically unsaturated monomers containing these functionalities orby post functionalization of a polymer with additional reactions afterpolymerization; and wherein the processing aid polymer has a Mw equal toor greater than 700,000. In such embodiment, the first stage contains nounits derived from functionalized monomers.

A second embodiment of the multi-stage emulsion processing aid polymercomprises from 25 to 75 percent by weight first stage polymer whichcomprises 0 to 99.6 mole % units derived from one or more non-functionalethylenically unsaturated monomer(s) and 0.4 to 100 mole % units derivedfrom one or more functionalized ethylenically unsaturated monomer(s)into the emulsion polymerization reactor, wherein the functionality isselected from the group consisting of β-keto esters, β-keto amides,β-diketones, cyanoacetic esters, malonates, nitroalkanes, β-nitroesters, sulfonazides, thiols, thiol-s-triazines, and amine, where thefunctionality is incorporated into polymers by polymerizing,ethylenically unsaturated monomers containing these functionalities orby post functionalization of a polymer with additional reactions afterpolymerization; and from 25 to 75 percent by weight second stage polymerwhich comprises units derived from non-functional ethylenicallyunsaturated monomer; and wherein the processing aid polymer has a Mwequal to or greater than 700,000. In such embodiment, the second stagecontains no units derived from functionalized monomers.

All individual values and subranges from 25 to 75 percent by weightfirst stage are included herein and disclosed herein; for example, thefirst stage in the multi-stage polymer can be from a lower limit of 25,30, 35, 40, 45, 50, 55, 60, 65, or 70 weight percent to an upper limitof 30, 35, 40, 45, 50, 55, 60, 65, 70 or 75 weight percent. For example,the weight percent of first stage may be in the range of from 25 to 75weight percent, or in the alternative, from 25 to 50 weight percent, orin the alternative from 40 to 70 weight percent.

All individual values and subranges from 25 to 75 percent second stageby are included herein and disclosed herein; for example, the weightpercent of the second stage in the multi-stage polymer can be from alower limit of 25, 30, 35, 40, 45, 50, 55, 60, 65, or 70 weight percentto an upper limit of 30, 35, 40, 45, 50, 55, 60, 65, 70 or 75 weightpercent. For example, the weight percent of weight of the second stagemay be in the range of from 25 to 75 weight percent, or in thealternative, from 50 to 75 weight percent, or in the alternative from 30to 60 weight percent.

The processing aid polymer may have a weight average molecular weight(Mw) of equal to or greater than 700,000. All individual values andsubranges of equal to or greater than 700,000 are disclosed herein andincluded herein. For example the Mw of the processing aid polymer may befrom a lower limit of 700,000; 800,000; 900,000; 1 million; 1.2 million;1.4 million; 1.6 million; or 1.8 million.

The invention further provides a multi-stage emulsion processing aidpolymer according to any one of the foregoing embodiments wherein thefunctionalized ethylenically unsaturated monomer is selected from thegroup of β-keto esters and amides, β-diketones, cyanoacetic esters,malonates, nitroalkanes and β-nitro esters.

The invention further provides a multi-stage emulsion processing aidpolymer according to any one of the foregoing embodiments wherein thefunctionalized ethylenically unsaturated monomer is selected from thegroup of acetoacetoxyethyl(meth)acrylate (AAEM),acetoacetoxypropyl(meth)acrylate, acetoacetoxybutyl(meth)acrylate, 2,3-di(acetoacetoxy)propyl(meth)acrylate,acetoacetoxyethyl(meth)acrylamide, 2-cyanoacetoxyethyl(meth)acrylate,2-cyanoacetoxyethyl(meth)acrylamide,N-cyanoacetyl-N-metylaminoethyl(meth)acrylate, N-(2propionylacetoxybutyl) (meth)acrylamide.

The invention further provides a multi-stage emulsion processing aidpolymer according to any one of the foregoing embodiments wherein thefunctionalized ethylenically unsaturated monomer is AAEM.

Suitable for use as nonfunctional co-monomers (with the functionalizedmonomers described above) in the processing aid polymers aremonoethylenically unsaturated monomers such as alkyl acrylates in whichthe alkyl group contains no more than eighteen carbon atoms, preferablyno more than eight carbon atoms; alkyl methacrylates in which the alkylportion contains no more than eighteen carbon atoms, preferably no morethan eight carbon atoms; acrylonitrile; methacrylonitrile; acrylic acid;methacrylic acid; styrene; and substituted styrenes particularly alkylsubstituted styrenes wherein the alkyl group contains no more thanfourteen carbon atoms, and other vinyl monomers like vinyl chloride,ethylene, vinyl acetate and vinyl versitate. Typical of the suitableco-monomers are ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate,methyl methacrylate, butyl methacrylate, tert-butyl methacrylate,cyclohexyl methacrylate, hydroxyethylmethacrylate, acrylonitrile,methacrylonitrile, acrylic acid, methacrylic acid, styrene,o-chlorostyrene and α-methyl styrene. Styrene, acrylonitrile, butylacrylate, butyl methacrylate, ethyl acrylate, methyl methacrylate, andcombinations thereof are the preferred monomers. Likewise thefunctionality can be polymerized into a copolymer of polyethylene thatis then chlorinated to make the processing aid polymer compatible withPVC or other halogenated polymers.

In an alternative embodiment, the instant invention further provides amulti-stage emulsion polymerization process comprising: feeding water,at least one non-functionalized ethylenically unsaturated monomer andsurfactant into an emulsion polymerization reactor, thereby forming afirst stage polymer of a multi-stage emulsion polymer wherein the firststage polymer comprises from 25% to 75% by weight of the total weight ofthe multistage emulsion polymer; feeding one or more functionalizedethylenically unsaturated monomer into the emulsion polymerizationreactor, wherein the functionality is selected from the group consistingof β-keto esters, β-keto amides, β-diketones, cyanoacetic esters,malonates, nitroalkanes, β-nitro esters, sulfonazides, thiols,thiol-s-triazines, and amine, where the functionality is incorporatedinto polymers by polymerizing, ethylenically unsaturated monomerscontaining these functionalities or by post functionalization of apolymer with additional reactions after polymerization, into theemulsion polymerization reactor to form a second stage polymer, in thepresence of the first stage polymer, wherein the second stage polymercomprises from 25% to 75% by weight of the total weight of themultistage emulsion polymer; and drying, or allowing to dry, themultistage emulsion polymer thereby forming a multistage emulsionpolymer processing aid.

In an alternative embodiment, the instant invention further provides amulti-stage emulsion polymerization process comprising: feeding water,one or more functionalized ethylenically unsaturated monomer into theemulsion polymerization reactor, wherein the functionality is selectedfrom the group consisting of β-keto esters, β-keto amides, β-diketones,cyanoacetic esters, malonates, nitroalkanes, β-nitro esters,sulfonazides, thiols, thiol-s-triazines, and amine, where thefunctionality is incorporated into polymers by polymerizing,ethylenically unsaturated monomers containing these functionalities orby post functionalization of a polymer with additional reactions afterpolymerization, and surfactant into an emulsion polymerization reactor,thereby forming a first stage polymer of a multi-stage emulsion polymerwherein the first stage polymer comprises from 25% to 75% by weight ofthe total weight of the multistage emulsion polymer; feeding at leastone non-functionalized ethylenically unsaturated monomer into theemulsion polymerization reactor, to form a second stage polymer, in thepresence of the first stage polymer, wherein the second stage polymercomprises from 25% to 75% by weight of the total weight of themultistage emulsion polymer, and drying, or allowing to dry, themultistage emulsion polymer thereby forming a multistage emulsionpolymer processing aid.

In an alternative embodiment, the instant invention further provides aprocess for producing a foamable halogenated polymer formulationcomprising: blending (a) from 20 to 99% by weight of one or morehalogenated polymers selected from homopolymers or copolymers comprisingat least 80% by weight of the halogenated polymer of one or moremonomers selected from vinyl chloride, vinyl fluoride, vinylidenechloride, and vinylidene fluoride, and chlorinated polyvinyl chloride,and chlorinated polyethylene; with from 0.5 to 20% by weight of one ormore multistage emulsion polymer processing aid produced according to anembodiment of the inventive process.

In an alternative embodiment, the instant invention further provides theprocess according to any one of the foregoing embodiments wherein thefunctionalized ethylenically unsaturated monomer is selected from thegroup of β-keto esters and amides, β-diketones, cyanoacetic esters,malonates, nitroalkanes and β-nitro esters. In an alternativeembodiment, the instant invention further provides the process accordingto any one of the foregoing embodiments wherein the substitutedethylenically unsaturated monomer is selected from the group ofacetoacetoxyethyl(meth)acrylate, acetoacetoxypropyl(meth)acrylate,acetoacetoxybutyl(meth)acrylate, 2, 3-di(acetoacetoxy)propyl(meth)acrylate, acetoacetoxyethyl(meth)acrylamide,2-cyanoacetoxyethyl(meth)acrylate, 2-cyanoacetoxyethyl(meth)acrylamide,N-cyanoacetyl-N-metylaminoethyl(meth)acrylate, N-(2propionylacetoxybutyl) (meth)acrylamide.

In an alternative embodiment, the instant invention further provides theprocess according to any one of the foregoing embodiments wherein thefunctionalized ethylenically unsaturated monomer is acetoacetoxyethylmethacrylate (AAEM).

The functional groups can be incorporated into processing aid polymersby the copolymerization of ethylenically unsaturated monomers thatcontain these functionalities with other ethylenically unsaturatedmonomers used to make such processing aid polymers. Polymerization canbe by solution, suspension, emulsion, or bulk polymerization providedthe polymerization results in random copolymers. Such functionalitiesare activated methylene or methyne groups that can be involved inMichael addition reactions. Such functional groups include β-keto estersand amides, β-diketones, cyanoacetic esters, malonates, nitroalkanes andβ-nitro esters.

Alternately, the functional groups can be incorporated into theprocessing aid polymer by making the polymer and then postfunctionalizing it with subsequent reactions. For example, a polymercontaining β-keto ester functional groups can be produced by postfunctionalizing a hydroxyl containing polymer with diketene.

Another useful additional functional group that can be incorporated intomonomers for polymerization is sulfonazide, (a.k.a. sulphonazide).Examples of how to make these sulfonazide-containing monomers are givenin GB 1138929. Vinyl, vinylidene, and styryl compounds containing thesulphonazide groups are such suitable monomers. Particularly interestingexamples of such monomers in GB 1138929 are m- andp-methacryloylaminophenyl sulphonazide, m- and p-acryloylaminophenylsulphonazide, and reaction products of 1 mole of 3- or4-sulphonazidophenyl isocyanate with 1 mole of vinyl or vinylidenemonomers containing hydroxyl groups, for example withhydroxypropyl(meth)acrylate or hydroxyethyl(meth)acrylate.

Other reactive functionality to incorporate into processing aid polymersby the appropriate monomers or post functionalization of a polymer afterpolymerization are thiol, thiol-s-triazines, and amino functionality.

The functional monomers are used at levels of 0.4 to 100 mole % in thepolymer stage containing functional monomer. All individual values andsubranges from 0.4 to 100 mole % are disclosed and included herein; forexample, the amount of units derived from functional monomers may befrom a lower limit of 0.4, 10, 20, 30, 40, 50, 60, 70, 80, or 90 mole %to an upper limit of 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 mole %.For example, the amount of units derived from functional monomers may bein the range from 0.4 to 100 mole %, or in the alternative, from 10 to90 mole %, or in the alternative, from 0.5 to 20 mole %.

In the stage containing one or more functional monomer(s), one or morenon-functional monomer(s) are used at level from 0 to 99.6 mole %. Allindividual values and subranges from 0 to 99.6 mole % units derived fromone or more non-functional ethylenically unsaturated monomer(s) areincluded herein and disclosed herein; for example the amount of unitsderived from one or more non-functional unsaturated monomer(s) can befrom a lower limit of 0, 10, 20, 30, 40, 50, 60, 70, 80, or 90 molepercent (mole %) to an upper limit of 10, 20, 30, 40, 50, 60, 70, 80,90, or 99.6 mole %. For example, the amount of non-functionalethylenically unsaturated monomer(s) may be in the range from 0 to 99.6mole %, or in the alternative, from 20 to 90 mole %, or in thealternative, from 30 to 80 mole %, or in the alternative, from 0 to 75mole %.

Since a crosslinking or curing reaction is thought to occur between thefunctional groups of the processing aid and the halogenated polymer as ameans of lightly crosslinking the system to control melt viscosity,there is a desired range of functionality in terms of moles offunctionality provided by the processing aid per 100 grams ofhalogenated polymer.

Too low a level of functionality and the desired increase in meltviscosity will not occur. Too high a level of functionality and too muchinsoluble gel will occur and the halogenated polymer will no longer beprocessible as a thermoplastic. The desired range is 0.00040 to 0.0056moles of monomer repeat units of one or more of the listedfunctionalities per 100 grams of halogenated polymer. Loading levels of0.5 to 20 parts per hundred based on halogenated polymer of theprocessing aid can be used to deliver the functionality where the usepercentage will depend on the level of functionality in the processingaid.

In some embodiments, the processing aid polymers are materials with aweight average molecular weight from from 0.7 to 13 million, or in thealternative, from 1 to 13 million, or in the alternative, from 1.6 to 13million. The definition of weight average molecular weight is found inThe Elements of Polymer Science and Engineering, Alfred Rudin, AcademicPress, p. 42, 1982. The method of molecular weight measurement is givenin the experimental test method section below.

The processing aid polymers preferably have a Tg greater than 10° C. andbelow 150° C. An even more desired range is 55° C. to 150° C. as thismakes it easier to isolate the polymer as powder or pellets. “Tg” is the“glass transition temperature” of a polymeric phase. The glasstransition temperature of a polymer is the temperature at which apolymer transitions from a rigid, glassy state at temperatures below itsTg to a fluid or rubbery state at temperatures above Tg. The Tg of apolymer is measured by differential scanning calorimetry (DSC) using themid-point in the heat flow versus temperature transition as the Tgvalue. For the purposes of this measurement, a heating rate for the DSCmeasurement is 20° C. per minute.

The processing aid polymers should be compatible with the basehalogenated polymer(s) that is/are being foamed. By “compatible” we meanthat the processing aid polymer mixes or disperses uniformly into thebase polymer during thermal processing. The mixture may not be opticallyclear, but a single glass transition temperature, Tg, for the blendedpolymers is generally seen. At the very least, if separate Tgs are seenfor the blended polymers, they are shifted by the presence of the otherpolymer(s).

The processing aid polymers are typically isolated to form afree-flowing powder or pellets, the powder particles having a 50-500micron mean diameter. This processing aid polymer is subsequently addedto thermoplastic foam formulations.

The foamable polymer formulation of this invention optionally furthercomprises 0.1 to 6% by weight of a blowing agent. All individual valuesand subranges from 0.1 to 6% by weight are included herein and disclosedherein; for example, the amount of blowing agent in the formulation canbe from a lower limit of 0.1, 1.5, 2, 2.5, 3, 3.8, 4, 4.5, 5 or 5.8% byweight to an upper limit of 0.5, 1.2, 2.6, 3.9, 4, 5.3 or 6% by weight.For example, the amount of blowing agent in the polymer formulation maybe in the range of from 0.1 to 6% by weight, or in the alternative, from1 to 5% by weight.

In another embodiment, the invention provides a process for producing afoamable halogenated polymer formulation comprising: blending (a) from20 to 99% by weight of one or more halogenated polymers (A) selectedfrom. homopolymers or copolymers comprising at least 80% by weight ofthe halogenated polymer of one or more monomers selected from vinylchloride, vinyl fluoride, vinylidene chloride, and vinylidene fluoride,and chlorinated polyvinyl chloride, and chlorinated polyethylene; with(b) one or more multi-stage emulsion processing aid polymer having afunctional group monomer incorporated into the second stage wherein theone or more the processing aid polymers is used at a level in theformulation to provide 0.00040 to 0.0056 moles of monomer repeat unitsof one or more functionalities per 100 g of halogenated polymers.

In another embodiment, the invention provides a process for producing afoamable halogenated polymer formulation comprising: blending (a) from20 to 99% by weight of one or more halogenated polymers (A) selectedfrom. homopolymers or copolymers comprising at least 80% by weight ofthe halogenated polymer of one or more monomers selected from vinylchloride, vinyl fluoride, vinylidene chloride, and vinylidene fluoride,and chlorinated polyvinyl chloride, and chlorinated polyethylene; with(b) one or more multistage emulsion processing aid polymer having afunctional group monomer incorporated into the first stage wherein theone or more the processing aid polymers is used at a level in theformulation to provide 0.00040 to 0.0056 moles of monomer repeat unitsof one or more functionalities per 100 g of halogenated polymers.

All values and subranges from 00.00040 to 0.0056 moles of monomer repeatunits of one or more functionalities per 100 g of halogenated polymersare included herein and disclosed herein; for example the level ofprocessing aid used in forming the foaming halogenated processing aidmay be from a lower limit of 00.00040, 0.00095, 0.0015, 0.0025, 0.0035,0.0045 or 0.005 moles of monomer repeat units of one or morefunctionalities per 100 g of halogenated polymers to an upper limit of0.00095, 0.0015, 0.0025, 0.0035, 0.0045, 0.005, or 0.0056 moles ofmonomer repeat units of one or more functionalities per 100 g ofhalogenated polymers. For example, the amount of processing aid polymerused in the foamable halogenated polymer formulation may be from00.00040 to 0.0056, or in the alternative, from 0.00065 to 0.0015, or inthe alternative from 0.00095 to 0.005 moles of monomer repeat units ofone or more functionalities per 100 g of halogenated polymers.

Chemical blowing agents can be any of a variety of chemical blowingagents which release a gas upon thermal decomposition. The blowing agentor mixtures of agents can be selected from chemicals containingdecomposable groups such as azo, N-nitroso, carboxylate, carbonate,heterocyclic nitrogen-containing and sulfonyl hydrazide groups.Generally, they are solid materials that liberate gas(es) when heated bymeans of a chemical reaction or upon decomposition. Representativecompounds include azodicarbonamide and derivatives, bicarbonates,hydrazine derivatives, semicarbazides, tetrazoles, benzoxazines, andborohydrates as outlined in Plastic Additives Handbook, Ch. 16, eds. R.Gachter, H. Muller, and P. P. Klemchuk, Hanser Gardner Publishers,Cincinnati (1996). Examples of these blowing agents areazodicarbonamide, 4,4-oxybis(benzenesulfohydrazide),diphenylsulfone-3,3-disulfohydrazide, trihydrazinotriazine,p-toluylenesulfonyl semicarbazide, 5-phenyltetrazole, isatoic anhydride,sodium bicarbonate, and sodium borohydride. In addition to chemicalblowing agents, physical blowing agents such as gases and volatileliquids can also be used. Foaming can be generated by super criticalgases like CO₂ that are injected into the extruder.

The blowing agent may be added to the polymer in several different wayswhich are known to those skilled in the art, for example, by adding thesolid powder, liquid or gaseous agents directly to the resin in theextruder while the resin is in the molten state to obtain uniformdispersal of the agent in the molten plastic. Preferably the blowingagent is added before the extrusion process and is in the form of asolid. The temperature and pressures to which the foamable compositionof the invention are subjected to provide a foamed composition will varywithin a wide range, depending upon the amount and type of foaming agentthat is used.

In addition to the matrix halogenated polymer, functional polymerprocessing aid and blowing agent, formulations can include thermalstabilizers, light stabilizers, antioxidants, impact modifiers,lubricants, waxes, plasticizers, fillers, fibers, pigments, conventionalor nonfunctional processing aid polymers, and other common additives.

EXAMPLES

The following examples illustrate the present invention but are notintended to limit the scope of the invention.

Inventive Examples 1 and 3 were prepared by synthesizing processing aidpolymers having AAEM added in the first stage of the multistage emulsionpolymerization. The multistage emulsion polymerization was conducted asfollows:

Inventive Example 1 0.000224 mol AAEM per 1.0 g of Processing AidPolymer

A 5 L round bottom flask was fitted with a stirrer, temperaturecontroller, nitrogen line and condenser. 1245 g of deionized (DI) water,0.1 g sodium hydroxide (50% aqueous) and 9.84 g DOWFAX 2A1 (46% active)were charged to the kettle. The mixture was warmed under a nitrogensparge to 40° C. The sparge was switched to a sweep. A monomer mixtureof 27.05 g BMA, 81.16 g BA, 569.54 g MMA and 77.66 g AAEM was prepared,and then added to the kettle. Next, a solution of 0.30 g sequestrene (5%active), 0.11 g disodium EDTA and 10 g DI water was added to thereactor. Then, 0.83 g sodium persulfate in 10 g DI water was added.Next, a mixture of 0.10 g lykopon and 0.09 g sodium formaldehydesulfoxylate in 10 g DI water was added. The reaction was observed toincrease in temperature by 41.2° C. over 63 minutes. After reaching peakexotherm, the reaction was cooled to 40° C. Next, 39.38 g DOWFAX 2A1(46% active) in 20 g DI water was added to the kettle. Then, a monomermixture of 34.43 g BMA, 103.29 g BA and 724.86 g MMA was prepared andadded to the kettle. Next, 0.08 g sodium formaldehyde sulfoxylate in 10g DI water was added to the kettle. Then, 0.13 g of t-butylhydroperoxide(70% active) in 10 g DI water was added to the kettle. The reaction wasobserved to increase in temperature by 45.3° C. over 33 minutes. Thereaction was cooled to 75° C. and 10.82 g DOWFAX 2A1 (46% active) in 10g DI water was added. The reaction was cooled to 60° C. and 0.70 gsodium persulfate in 10 g DI water was added and the reaction was heldat 60° C. for 30 minutes. The reaction was cooled to 50° C. and 0.63 gsodium sulfate in 10 g DI water was added. The reaction was cooled to40° C. and filtered through a mesh cloth (52.5% solids).

Inventive Example 3 0.000112 mol AAEM per 1.0 g of Processing AidPolymer

A 5 L round bottom flask was fitted with a stirrer, temperaturecontroller, nitrogen line and condenser. 1245 g of deionized (DI) water,0.1 g sodium hydroxide (50% aqueous) and 9.84 g DOWFAX 2A1 (46% active)were charged to the kettle. The mixture was warmed under a nitrogensparge to 40° C. The sparge was switched to a sweep. A monomer mixtureof 27.05 g BMA, 92.55 g BA, 575.23 g MMA and 38.83 g AAEM was prepared,then added to the kettle. Next, a solution of 0.30 g sequestrene (5%active), 0.11 g disodium EDTA and 10 g DI water was added to thereactor. Then, 0.83 g sodium persulfate in 10 g DI water was added.Next, a mixture of 0.10 g lykopon and 0.09 g sodium formaldehydesulfoxylate in 10 g DI water was added. The reaction was observed toincrease in temperature by 39.3° C. over 61 minutes. After reaching peakexotherm, the reaction was cooled to 40° C. Next, 39.38 g DOWFAX 2A1(46% active) in 20 g DI water was added to the kettle. Then, a monomermixture of 34.43 g BMA, 117.79 g BA and 732.11 g MMA was prepared andadded to the kettle. Next, 0.08 g sodium formaldehyde sulfoxylate in 10g DI water was added to the kettle. Then, 0.13 g of t-butylhydroperoxide(70% active) in 10 g DI water was added to the kettle. The reaction wasobserved to increase in temperature by 49.0° C. over 39 minutes. Thereaction was cooled to 75° C. and 10.82 g DOWFAX 2A1 (46% active) in 10g DI water was added. The reaction was cooled to 60° C. and 0.70 gsodium persulfate in 10 g DI water was added and the reaction was heldat 60° C. for 30 minutes. The reaction was cooled to 50° C. and 0.63 gsodium sulfate in 10 g DI water was added. The reaction was cooled to40° C. and filtered through a mesh cloth (52.8% solids).

Inventive Examples 2 and 4 were prepared by synthesizing processing aidpolymers having AAEM added in the second stage of the multistageemulsion polymerization. The multistage emulsion polymerization wasconducted as follows:

Inventive Example 2 0.000224 mol AAEM per 1.0 g of Processing AidPolymer

A 5 L round bottom flask was fitted with a stirrer, temperaturecontroller, nitrogen line and condenser. 1245 g of deionized (DI) water,0.1 g sodium hydroxide (50% aqueous) and 9.84 g DOWFAX 2A1 (46% active)were charged to the kettle. The mixture was warmed under a nitrogensparge to 40° C. The sparge was switched to a sweep. A monomer mixtureof 27.05 g BMA, 81.16 g BA and 569.54 g MMA was prepared, then added tothe kettle. Next, a solution of 0.30 g sequestrene (5% active), 0.11 gdisodium EDTA and 10 g DI water was added to the reactor. Then, 0.83 gsodium persulfate in 10 g DI water was added. Next, a mixture of 0.10 glykopon and 0.09 g sodium formaldehyde sulfoxylate in 10 g DI water wasadded. The reaction was observed to increase in temperature by 37.9° C.over 88 minutes. After reaching peak exotherm, the reaction was cooledto 40° C. Next, 39.38 g DOWFAX 2A1 (46% active) in 20 g DI water wasadded to the kettle. Then, a monomer mixture of 34.43 g BMA, 103.29 gBA, 724.86 g MMA and 77.66 g AAEM was prepared and added to the kettle.Next, 0.08 g sodium formaldehyde sulfoxylate in 10 g DI water was addedto the kettle. Then, 0.13 g of t-butylhydroperoxide (70% active) in 10 gDI water was added to the kettle. The reaction was observed to increasein temperature by 49.6° C. over 42 minutes. The reaction was cooled to75° C. and 10.82 g DOWFAX 2A1 (46% active) in 10 g DI water was added.The reaction was cooled to 60° C. and 0.70 g sodium persulfate in 10 gDI water was added and the reaction was held at 60° C. for 30 minutes.The reaction was cooled to 50° C. and 0.63 g sodium sulfate in 10 g DIwater was added. The reaction was cooled to 40° C. and filtered througha mesh cloth (52.2% solids).

Inventive Example 4 0.000112 mol AAEM per 1.0 g of Processing AidPolymer

A 5L round bottom flask was fitted with a stirrer, temperaturecontroller, nitrogen line and condenser. 1245 g of deionized (DI) water,0.1 g sodium hydroxide (50% aqueous) and 9.84 g DOWFAX 2A1 (46% active)were charged to the kettle. The mixture was warmed under a nitrogensparge to 40° C. The sparge was switched to a sweep. A monomer mixtureof 27.05 g BMA, 92.55 g BA and 575.23 g MMA was prepared, then added tothe kettle. Next, a solution of 0.30 g sequestrene (5% active), 0.11 gdisodium EDTA and 10 g DI water was added to the reactor. Then, 0.83 gsodium persulfate in 10 g DI water was added. Next, a mixture of 0.10 glykopon and 0.09 g sodium formaldehyde sulfoxylate in 10 g DI water wasadded. The reaction was observed to increase in temperature by 38.6° C.over 82 minutes. After reaching peak exotherm, the reaction was cooledto 40° C. Next, 39.38 g DOWFAX 2A1 (46% active) in 20 g DI water wasadded to the kettle. Then, a monomer mixture of 34.43 g BMA, 117.79 gBA, 732.11 g MMA and 38.83 g AAEM was prepared and added to the kettle.Next, 0.08 g sodium formaldehyde sulfoxylate in 10 g DI water was addedto the kettle. Then, 0.13 g of t-butylhydroperoxide (70% active) in 10 gDI water was added to the kettle. The reaction was observed to increasein temperature by 49.2° C. over 35 minutes. The reaction was cooled to75° C. and 10.82 g DOWFAX 2A1 (46% active) in 10 g DI water was added.The reaction was cooled to 60° C. and 0.70 g sodium persulfate in 10 gDI water was added and the reaction was held at 60° C. for 30 minutes.The reaction was cooled to 50° C. and 0.63 g sodium sulfate in 10 g DIwater was added. The reaction was cooled to 40° C. and filtered througha mesh cloth (52.8% solids).

Comparative Examples 1 and 2 were prepared by synthesizing processingaid polymers having AAEM added in both the first and second stages ofthe multistage emulsion polymerization. The multistage emulsionpolymerization was conducted as follows:

Comparative Example 1 0.000224 mol AAEM per 1.0 g of Processing AidPolymer

A 5 L round bottom flask was fitted with a stirrer, temperaturecontroller, nitrogen line and condenser. 1245 g of deionized (DI) water,0.1 g sodium hydroxide (50% aqueous) and 9.84 g DOWFAX 2A1 (46% active)were charged to the kettle. The mixture was warmed under a nitrogensparge to 40° C. The sparge was switched to a sweep. A monomer mixtureof 27.05 g BMA, 81.16 g BA, 569.54 g MMA and 34.17 g AAEM was prepared,then added to the kettle. Next, a solution of 0.30 g sequestrene (5%active), 0.11 g disodium EDTA and 10 g DI water was added to thereactor. Then, 0.83 g sodium persulfate in 10 g DI water was added.Next, a mixture of 0.10 g lykopon and 0.09 g sodium formaldehydesulfoxylate in 10 g DI water was added. The reaction was observed toincrease in temperature by 42.4° C. over 75 minutes. After reaching peakexotherm, the reaction was cooled to 40° C. Next, 39.38 g DOWFAX 2A1(46% active) in 20 g DI water was added to the kettle. Then, a monomermixture of 34.43 g BMA, 103.29 g BA, 724.86 g MMA and 43.49 g AAEM wasprepared and added to the kettle. Next, 0.08 g sodium formaldehydesulfoxylate in 10 g DI water was added to the kettle. Then, 0.13 g oft-butylhydroperoxide (70% active) in 10 g DI water was added to thekettle. The reaction was observed to increase in temperature by 47.4° C.over 34 minutes. The reaction was cooled to 75° C. and 10.82 g DOWFAX2A1 (46% active) in 10 g DI water was added. The reaction was cooled to60° C. and 0.70 g sodium persulfate in 10 g DI water was added and thereaction was held at 60° C. for 30 minutes. The reaction was cooled to50° C. and 0.63 g sodium sulfate in 10 g DI water was added. Thereaction was cooled to 40° C. and filtered through a mesh cloth (52.5%solids).

Comparative Example 2 0.000112 mol AAEM per 1.0 g of Processing AidPolymer

A 5 L round bottom flask was fitted with a stirrer, temperaturecontroller, nitrogen line and condenser. 1245 g of deionized (DI) water,0.1 g sodium hydroxide (50% aqueous) and 9.84 g DOWFAX 2A1 (46% active)were charged to the kettle. The mixture was warmed under a nitrogensparge to 40° C. The sparge was switched to a sweep. A monomer mixtureof 27.05 g BMA, 92.55 g BA, 575.23 g MMA and 17.09 g AAEM was prepared,then added to the kettle. Next, a solution of 0.30 g sequestrene (5%active), 0.11 g disodium EDTA and 10 g DI water was added to thereactor. Then, 0.83 g sodium persulfate in 10 g DI water was added.Next, a mixture of 0.10 g lykopon and 0.09 g sodium formaldehydesulfoxylate in 10 g DI water was added. The reaction was observed toincrease in temperature by 40.3° C. over 80 minutes. After reaching peakexotherm, the reaction was cooled to 40° C. Next, 39.38 g DOWFAX 2A1(46% active) in 20 g DI water was added to the kettle. Then, a monomermixture of 34.43 g BMA, 117.79 g BA, 732.11 g MMA and 21.75 g AAEM wasprepared and added to the kettle. Next, 0.08 g sodium formaldehydesulfoxylate in 10 g DI water was added to the kettle. Then, 0.13 g oft-butylhydroperoxide (70% active) in 10 g DI water was added to thekettle. The reaction was observed to increase in temperature by 49.2° C.over 42 minutes. The reaction was cooled to 75° C. and 10.82 g DOWFAX2A1 (46% active) in 10 g DI water was added. The reaction was cooled to60° C. and 0.70 g sodium persulfate in 10 g DI water was added and thereaction was held at 60° C. for 30 minutes. The reaction was cooled to50° C. and 0.63 g sodium sulfate in 10 g DI water was added. Thereaction was cooled to 40° C. and filtered through a mesh cloth (52.6%solids).

Emulsions were converted to powder by oven drying at 60° C. Likewise theemulsions can be dried by any of the methods know to the art such as:spray drying, fluid bed drying, coagulation followed by drying, etc.

Each of the Inventive and Comparative Examples were blended with amasterbatch, prepared as set forth in Table 1.

TABLE 1 MATERIAL AVAILABLE FROM PHR PVC (FORMOLON F614 (K = 59)) FormosaPlastics 100 Stabilizer (ADVASTAB TM-181) The Dow Chemical 2.5 CompanyCalcium Stearate Compton 1.3 Paraffin Wax (AMERILUBE XL 165) AmericanSynthol 0.8 Oxidized PE wax (AC-629) Honeywell 0.20 Lubricant (ADVALUBEB3310) The Dow Chemical 0.60 Company PARALOID K175 (processing aid) TheDow Chemical 2 Company Blowing agent (FICEL ES55 HVC)* Lanxess Co. 0.7Titanium dioxide (TIONA RCL-4) Millennium Chemicals 2.5 Calciumcarbonate (OMYACARB Omya Inc. 10 UFT) *Blowing agent is a blend ofazodicarbonamide and sodium bicarbonate.

The components were blended in a Henschel blender to make a masterbatch. After the PVC was charged and the blades begin turning, theblender temperature increased from frictional heating at approximately3-5° C/min. After the PVC was charged, the remaining ingredients wereadded through the addition port when the temperature reached thetemperatures listed below.

Charge PVC to blender at 25° C. and close lid. Turn on mixing blades atabout 1000 rpm. Monitor temperature. No cooling. Add ADVASTAB TM-181stabilizer at 52° C. Add ADVALUBE B3310, paraffin wax, XL-165, AC-629A,and calcium stearate at 66° C. Add lubricating processing aid, PARALOIDK-175 and blowing agent, Ficel ES55 HVC, at 77° C. Add the Titaniumdioxide and calcium carbonate at 90.degree. C. At 100° C. start coolingwater flow. Reduce blade speed to near minimum (ca. 200 rpm). Cool to45° C., turn off blades, and remove masterbatch powder from blender.

The formulated PVC was extruded on a Haake, Polylab twin screw, counterrotating extruder. Zone 1 was set at 1550° C. Zone 2 was set at 175° C.Zone 3 was set at 180° C. The die was a coat hanger type die with a 50mm wide opening and a gap of 1 mm between the lips. The die temperaturewas set at 150° C. The extruder was run at 45 rpms and the PVC powderwas fed into the throat of the extruder by gravity feed. Coming out ofthe extruder, the foamed PVC was run through a 3 roll stacked coolingsetup set at 20° C. The gap between the cooling rolls was 2.79 mm.

Example processing aids were post added to the master batch at 10 partsper hundred on PVC (PHR) levels and mixed by shaking in a bag to makeexample formulations.

TABLE 2* Moles AAEM Solution per AAEM AAEM Viscosity 100 g Density GlossSample (wt %) Placement M_(w) (cps) PVC (g/mL) (75°) Comp. Ex. 1 4.8%Stages 1 & 2 1,370,000 122 0.00224 0.53 27 Inv. Ex. 1 4.8% Stage 12,234,250 186 0.00224 0.54 36 Inv. Ex. 2 4.8% Stage 2 4,050,150 4340.00224 0.52 44 Comp. Ex. 2 2.4% Stages 1 & 2 1,571,050 202 0.00112 0.5740 Inv. Ex. 3 2.4% Stage 1 2,318,800 278 0.00112 0.57 41 Inv. Ex. 4 2.4%Stage 2 3,987,150 1362 0.00112 0.57 47 *All data collected at 10 phrprocessing aid.

Definitions:

AAEM Level: Total amount of AAEM in the polymer composition, expressedas a weight percent of the polymer processing aid.

AAEM Placement: Where the AAEM was added to the polymerization, in Stage1, Stage 2 or both (this is a two stage polymer example).

Test Methods

Test methods include the following:

Molecular weight measurements by size exclusion chromatography (SEC)were performed as follows. Sample was prepared in tetrahydrofuran at aconcentration of about 1.0 mg/mL. The samples were shaken on shaker atleast overnight at room temperature. Sample solutions were filteredusing 0.45 μm PTFE filter before SEC analysis.

Separations were carried out at 40 C on a liquid chromatographconsisting of an Agilent (Santa Clara, Calif.) 1100 series pump,autosampler, and refractive index (RI) detector. System control, dataacquisition, and data processing were performed using Chemstationsoftware (Agilent).

SEC separations were performed in tetrahydrofuran at a flow rate of 1.0mL/min using two PLGel Mixed A columns (300.times.7.5 mm ID) packed withpolystyrene-divinylbenzene gel purchased from Polymer Laboratories (adivision of Agilent). 100 μL of sample solution with concentration ofabout 1.0 mg/mL was subjected for SEC separation. Weight average andnumber average molecular weight were recorded for each example.

Calibration: Polystyrene (PS) standards having M.sub.p in the range 580to 7,500,000 g/mol with concentration of about 0.5 mg/mL intetrahydrofuran were used to construct a 10 point calibration curve (1storder) which was used to evaluate the relative M of the analyzed sample.

Solution Viscosity in Acetone: 24 g of 40.5% solids emulsion was addedto an 8 oz jar containing 156 g acetone with mixing. After 2 hours ofmixing, the viscosity was measured on a Brookfield DV-II viscometerusing a #3 spindle at 60 rpm at room temperature. Solution viscosity isanother indication of molecular weight with higher viscositycorresponding to higher molecular weight.

Density was measured on the extruded foam strips by cutting 0.75 inch by1.25 inch pieces of foam from the strips. Density was determined usingthe method of ASTM D792. The thickness of the foam strips was determinedby measuring the maximum thickness of the strip using a digital caliper.Gloss was measured using a 75 degree micro-gloss meter from Gardner.

The present invention may be embodied in other forms without departingfrom the spirit and the essential attributes thereof, and, accordingly,reference should be made to the appended claims, rather than to theforegoing specification, as indicating the scope of the invention.

1. A multi-stage emulsion processing aid polymer comprising from 25 to75 percent by weight first stage polymer which comprises units derivedfrom non-functional ethylenically unsaturated monomer; and from 25 to 75percent by weight second stage polymer which comprises 0 to 99.6 mole %units derived from one or more non-functional ethylenically unsaturatedmonomer(s) and 0.4 to 100 mole % units derived from one or morefunctionalized ethylenically unsaturated monomer(s) into the emulsionpolymerization reactor, wherein the functionality is selected from thegroup consisting of β-keto esters, β-keto amides, β-diketones,cyanoacetic esters, malonates, nitroalkanes, β-nitro esters,sulfonazides, thiols, thiol-s-triazines, and amine, where thefunctionality is incorporated into polymers by polymerizing,ethylenically unsaturated monomers containing these functionalities orby post functionalization of a polymer with additional reactions afterpolymerization; and wherein the processing aid polymer has a Mw equal toor greater than 700,000.
 2. The multi-stage emulsion processing aidpolymer according to claim 1 wherein the functionalized ethylenicallyunsaturated monomer is selected from the group of β-keto esters andamides, β-diketones, cyanoacetic esters, malonates, nitroalkanes andβ-nitro esters.
 3. The multi-stage emulsion processing aid polymeraccording to claim 1, wherein the functionalized ethylenicallyunsaturated monomer is selected from the group ofacetoacetoxyethyl(meth)acrylate, acetoacetoxypropyl(meth)acrylate,acetoacetoxybutyl(meth)acrylate, 2,3-di(acetoacetoxy)propyl(meth)acrylate,acetoacetoxyethyl(meth)acrylamide, 2-cyanoacetoxyethyl(meth)acrylate,2-cyanoacetoxyethyl(meth)acrylamide,N-cyanoacetyl-N-metylaminoethyl(meth)acrylate, N-(2propionylacetoxybutyl) (meth)acrylamide.
 4. The multi-stage emulsionprocessing aid polymer according to claim 1, wherein the functionalizedethylenically unsaturated monomer is AAEM, wherein the processing aidpolymer has a Tg between 10° C. and 150° C.
 5. The multi-stage emulsionprocessing aid polymer according to claim 4 wherein the functionalizedethylenically unsaturated monomer is AAEM, wherein the processing aidpolymer has a Tg is between 55° C. and 150° C.
 6. The multi-stageemulsion processing aid polymer according to claim 1 wherein thefunctionalized ethylenically unsaturated monomer is AAEM, wherein theprocessing aid polymer has a Mw equal to or greater than 1.6 million. 7.A multi-stage emulsion processing aid polymer comprising from 25 to 75percent by weight first stage polymer which comprises 0 to 99.6 mole %units derived from one or more non-functional ethylenically unsaturatedmonomer(s) and 0.4 to 100 mole % units derived from one or morefunctionalized ethylenically unsaturated monomer(s) into the emulsionpolymerization reactor, wherein the functionality is selected from thegroup consisting of β-keto esters, β-keto amides, β-diketones,cyanoacetic esters, malonates, nitroalkanes, β-nitro esters,sulfonazides, thiols, thiol-s-triazines, and amine, where thefunctionality is incorporated into polymers by polymerizing,ethylenically unsaturated monomers containing these functionalities orby post functionalization of a polymer with additional reactions afterpolymerization; and from 25 to 75 percent by weight second stage polymerwhich comprises units derived from non-functional ethylenicallyunsaturated monomer; and wherein the processing aid polymer has a Mwequal to or greater than 700,000.
 8. The multi-stage emulsion processingaid polymer according to claim 7 wherein the functionalizedethylenically unsaturated monomer is AAEM, wherein the processing aidpolymer has a Tg between 10° C. and 150° C.
 9. The multi-stage emulsionprocessing aid polymer according to claim 7, wherein the functionalizedethylenically unsaturated monomer is AAEM, wherein the processing aidpolymer has a Tg is between 55° C. and 150° C.
 10. The multi-stageemulsion processing aid polymer according to claim 7, wherein thefunctionalized ethylenically unsaturated monomer is AAEM, wherein theprocessing aid polymer has a Mw equal to or greater than 1.6 million 11.A formulation comprising (a) from 20 to 99% by weight of one or morehalogenated polymers (A) selected from. homopolymers or copolymerscomprising at least 80% by weight of the halogenated polymer of one ormore monomers selected from vinyl chloride, vinyl fluoride, vinylidenechloride, and vinylidene fluoride, and chlorinated polyvinyl chloride,and chlorinated polyethylene; and (b) from 0.5 to 20% by weight of oneor more multi-stage processing aid polymers according to claim 1 whereinthe one or more the processing aid polymers is used at a level in theformulation to provide 0.00040 to 0.0056 moles of functionalized monomerrepeat units per 100 g of halogenated polymers.
 12. The formulationaccording to claim 11 wherein the functionalized ethylenicallyunsaturated monomer is selected from the group of β-keto esters andamides, β-diketones, cyanoacetic esters, malonates, nitroalkanes andβ-nitro esters.
 13. The formulation according to claim 11 wherein thefunctionalized ethylenically unsaturated monomer is selected from thegroup of acetoacetoxyethyl(meth)acrylate,acetoacetoxypropyl(meth)acrylate, acetoacetoxybutyl(meth)acrylate, 2,3-di(acetoacetoxy)propyl(meth)acrylate,acetoacetoxyethyl(meth)acrylamide, 2-cyanoacetoxyethyl(meth)acrylate,2-cyanoacetoxyethyl(meth)acrylamide,N-cyanoacetyl-N-metylaminoethyl(meth)acrylate, N-(2propionylacetoxybutyl) (meth)acrylamide.
 14. (canceled)
 15. (canceled)